1. Field of the Invention
The present invention relates to a hollow golf club head.
2. Description of the Related Art
Various shapes of soles are proposed in the hollow golf club head.
Paragraph [0038] of Japanese Patent Application Laid-Open No. 2005-143589 describes that a curvature radius of a sole is preferably 2.5 inches (63.5 mm) or greater and 4 inches (101.6 mm) or less.
Paragraph [0017] or the like of Japanese Patent Application Laid-Open No. 2004-135858 describes that a curvature radius of a sole in a face-back direction is 8.89 cm or greater and 15.24 cm or less. Paragraph [0072] of Japanese Patent Application Laid-Open No. 2004-135858 describes that the curvature radius of the sole in a toe-heel direction is 6.35 cm or greater and 8.89 cm or less. Paragraph [0073] of Japanese Patent Application Laid-Open No. 2004-135858 describes a case where the curvature radius of the sole in the toe-heel direction is greater than 8.89 cm.
[Claim 8] or the like of Japanese Patent Application Laid-Open No. 2003-265655 discloses a golf club head in which an average curvature radius of a sole in a toe-heel direction is 5.1 cm or greater and 7.6 cm or less and an average curvature radius thereof in a face-back direction is 8.9 cm or greater and 15.2 cm or less.